RECORDS MANAGEMENT

PUBLICATION NUMBER FIVE

The

Microfilming

User Manual

Government Records Service

March 2018

ii

Contents

Preface .................................................................................................................... v

Purpose of the Manual ....................................................................................... vi

Chapter 1 The Basics of Microfilming ............................................................. 1

1.1 General Characteristics of Microfilm

1.2 What is Microfilm

1.3 What is Microfilming

1.4 What is Micrographics

1.5 Microfilm Production Methods

1.6 Types of Microfilm

1.7 What is Microform

1.8 Common Formats of Microform

1.8.1 Microfilm Jacket

1.9 Microfilm Hardware

Chapter 2 Choosing Microfilming Applications .......................................... 12

2.1 Microfilm Versus Other Records Media

2.2 Advantages of Microfilming

2.3 Common Microfilming Applications

2.4 Limitations of Microfilm

2.5 The Choice of Microforms

2.6 Factors to Consider in Microfilming Conversion

2.7 Where to Microfilm

2.7.1 In-house Filming

2.7.2 Filming by External Service Provider

2.7.3 Microfilming by the Government Microfilm Centre

2.8 Checklists for Conversion

2.9 How to Start a Microfilming Project

iii

Chapter 3 Government Microfilm Centre (GMC) ......................................... 20

3.1 Establishment of GMC

3.2 Functions and Services of GMC

3.3 Records Filming Criteria of GMC

3.4 Procedures in Using GMC’s Services

3.5 Pre-filming Preparation of Source Documents

3.6 Request for Digitised Copy of Microfilmed Images

Chapter 4 Production Filming and Processing Control .............................. 25

4.1 General Requirements

4.2 Filming Archival Records, Permanent Records and Records for Legal

Acceptance

4.3 Proper Microfilming Procedures

4.3.1 Preparation before Microfilming

4.3.2 Actual Filming

4.3.3 Filming Sequence

4.4 Film Processing

4.4.1 Processing Elements

4.4.2 Choosing a Processor

4.4.3 Processing Control

Chapter 5 Microfilm Inspection, Duplication, Indexing and Retrieval .... 34

5.1 Quality Control Procedures

5.2 Microfilm Duplication

5.2.1 Different Generations of Microfilm

5.2.2 Factors to Consider in Making Film Duplicate

5.3 Microfilm Indexing and Retrieval

5.3.1 Different Types of Microfilm Indexing and Retrieval Methods

Chapter 6 Microfilm Maintenance .................................................................. 41

6.1 General Requirements

6.2 Proper Microfilm Handling

6.3 Proper Microfilm Storage Conditions

6.4 Microfilm Storage Equipment and Supplies

6.5 Disposal Requirements for Source Documents and Microfilm Records

6.6 Microfilm Standards

Glossary ............................................................................................................... 46

iv

Appendices .......................................................................................................... 52

A Return for Microfilming Services (GMC 1)

B Records Microfilming List (GMC 2A & 2B)

C Despatch of Records Microfilming List and Microfilm Records (GMC 3A)

D Receipt of Records Microfilming List and Microfilm Records (GMC 3B)

E Samples of Filming Targets

F Microfilm Inspection Report

G Defects Classification and Source Guide

H Resolution Test Chart for Planetary Camera

I Resolution Test Chart for Rotary Camera

Suggested Reading ............................................................................................. 64

Tables

1-1 Comparison of Five Different Types of Microfilm .................................... 3

2-1 Comparison of Paper, Electronic and Microfilm Records ....................... 12

2-2 Characteristics of Various Microforms .................................................... 15

4-1 Density Table ............................................................................................ 27

6-1 Storage Conditions for Microfilm ............................................................ 42

Figures

1-1 Quality Inspection Equipment .................................................................... 7

1-2 Digital Microfilm Retrieval System ........................................................... 9

1-3 Workflow in Source Document Microfilming ......................................... 11

3-1 Production Cycle in GMC ........................................................................ 24

4-1 Negative and Positive Images .................................................................. 29

5-1 Blip Mark Indexing .................................................................................. 39 40

v

Preface

The Microfilming User Manual is intended for managers

who do not have technical training in micrographics but

wish to use microfilming technology to improve the

management of government records. Officers-in-charge of

departmental micrographic operation will also benefit from

this publication which gives the details of current

government microfilming policy, guidelines and

requirements. Further technical information and advice can

also be obtained from the Government Records Service and

from the section on “Suggested Reading” listed in this

manual.

6

vi

Purpose of the Manual

This manual is for government bureaux and departments (B/Ds) to follow in

considering and carrying out microfilming operations. Its objectives are to:

a. Provide an overview of basic microfilming operation;

b. Explain the criteria of selecting records for microfilming;

c. Provide guidelines and standards for microfilming records;

d. Define the general procedures to be followed by B/Ds in microfilm production;

e. Introduce the microfilm services provided by the Government Microfilm Centre of

the Government Records Service (GRS) and the procedures in using its services;

and

f. Provide guidelines for the storage, handling and use of microfilm records and the

selection of retrieval equipment.

The provisions and processes set out in this manual are applicable primarily to silver

gelatine film. They are recommended for B/Ds when producing microfilm records in-

house or contracting for microfilm services from external service provider in order to

achieve image quality and stability.

B/Ds using microfilm records as court evidence should refer to sections 39 and 40 of

the Evidence Ordinance (Cap. 8). Please refer to Chapter 6 for more details regarding

the requirements of destroying the original documents after the production of microfilm

copy.

This manual does not include specific procedures to microfilm books, bound materials

or engineering and cartographic materials, nor does it cover the details of diazo,

vesicular, colour or computer output microfilm. B/Ds may contact the GRS for advice

on microfilming any type of records.

Definitions, procedures and technical requirements found in this manual are made with

reference to the standards and publications by the International Organization for

Standardization (ISO), and the American National Standards Institute/Association for

Information and Image Management (ANSI/AIIM) standards. A glossary of

terminology is provided at the end of the manual.

1

CHAPTER 1

The Basics of Microfilming

1.1 General Characteristics of Microfilm

Microfilm is a valuable tool in records management. It is a very stable medium for

recording documentary information and it is second only to good acid-free paper in its

permanence under suitable storage condition. Moreover, microfilm is well standardised,

court admissible and a technology-obsolescence proof medium for long-term storage in

both the government and private sectors.

Nevertheless, the photographic material nature of microfilm remains relatively fragile.

Microfilm will be unreadable if it is not produced correctly. It will deteriorate if it is

not processed properly. It is easily damaged when it is handled carelessly and it will

decay if it is stored in unsuitable conditions. Thus we need some basic understanding

of microfilming technology before we can make full use of it to meet specific needs and

requirements.

1.2 What is Microfilm

Microfilm is a fine grained high resolution film that can store images from textual,

graphic and computer records with the use of microphotography. It is a traditional

photographic material: a plastic, transparent support (base) coated with a photosensitive

material (emulsion) on one side.

1.3 What is Microfilming

Microfilming involves the use of a specialised type of camera to photograph records

and reduce them in size for storage. To be used, microfilm images must be magnified

and projected on a viewing screen known as microfilm-reader, or captured by electronic

means in a scanner and viewed on computer display.

1.4 What is Micrographics

Micrographics involves techniques and processes associated with the production,

handling and use of microfilm of different types and in different formats.

2

1.5 Microfilm Production Methods

There are primarily two types of microfilm production methods:

a. Source Document Microfilming in which microimages on film are produced by

photographing paper records.

b. Computer-Output-Microfilming (COM) in which microimages on film are

produced from digitally encoded data from computers without the use of paper.

This manual covers mainly the operation and control of source document microfilming

systems.

1.6 Types of Microfilm

Five types of microfilm are commonly used: Silver gelatine Film, Diazo Film,

Vesicular Film, Transparent Electrophotographic Film and Dry Silver Film. Table 1-1

gives a comparison of the five different types of microfilm.

a. Silver Gelatine Film

Silver gelatine film is used as original camera film and may also be used to make

duplicates. It requires wet processing and produces a reversed image (negative). Only

silver gelatine film is recommended for filming permanent records or records which

requires to be preserved for a long period of time.

Microfilm for permanent preservation must use polyester based silver gelatine film

which is chemically inert, dimensionally stable, resistant to tearing and inflammable.

When silver gelatine film on polyester base is properly processed and stored, it has a

life expectancy of 500 years.

b. Diazo Film

Diazo film contains layers of diazonium salt as dye in the emulsion. It is used

exclusively for duplicating and is a direct printing film (producing a negative duplicate

from a negative master and a positive duplicate from a positive master). Because of its

lower cost, high resolution capability and scratch resistance, it is often used for making

reference copies.

Diazo film, however, is relatively unstable and will fade especially when exposed to

light (e.g. prolonged exposure in a microfilm reader). It is not a permanent storage

medium.

3

Table 1-1 Comparison of Five Different Types of Microfilm

Film Type Durability

(Life Expectancy) Application

Wet

Processing Cost

Silver gelatine on

polyester base Long term (500 years)

Original and

duplicate Yes Expensive

Diazo Short to medium term

(10 years) Duplicate No Inexpensive

Vesicular Short to medium term

(10 years) Duplicate No Inexpensive

Transparent

Electrophotographic

Short to medium term

(10 years)

Updatable

microfiche No Inexpensive

Dry Silver Short to medium term

(10 years) COM No Fair

c. Vesicular Film

Vesicular film consists of small bubbles within a plastic layer and the bubbles scatter

light and thus producing a visible image. It is sign reversing which means it produces a

positive duplicate from a negative master and vice versa. Although it is commonly

used for the duplication of silver gelatine film, it is not recommended as permanent

storage medium for the bubbles in the film can be deformed upon the effect of elevated

temperature and pressure.

d. Transparent Electrophotographic Film

Transparent electrophotographic (TEP) film is a kind of microfiche with the advantage

of being updatable. Unlike the conventional silver gelatine microfilms which cannot be

changed once they are produced as the image forming process is irreversible, the

production of TEP film uses a photo-conductor to capture the latent images. Visible

images are formed by depositing and fixing carbon particles onto a polyester film base.

The newer images can be added onto the old images and therefore it is updatable. It

allows rapid processing and almost instant access to recorded information.

4

e. Dry Silver Film

Dry silver film or thermal-processed silver (TPS) film is used in specific COM

technologies to speed up image processing. As it does not require wet processing, the

turnaround time is faster. However, it does not meet the strict permanent storage

requirements established for wet processing and silver gelatine microfilm.

1.7 What is Microform

Microform is a generic term used to describe any of the various formats used in

micrographics.

1.8 Common Formats of Microform

The common formats of microform widely used by the government, academic

institutions or commercial organisations include the following:

a. 16mm and 35mm Roll Film

Roll film is an inexpensive microform containing a series of

images like a motion picture film but with no perforation along

the edges. While roll length varies, 100 feet in 0.005 inch in

thickness and 215 feet in 0.0025 inch in thickness are most

common.1 It is normally used for filming information that

needs to be kept in sequence. This type of packaging provides

file integrity as it ensures that documents filmed in sequence

are not lost or misfiled.

Roll film may be placed into a plastic film case known as

cartridge which protects the film from dust, fingerprints or

other damage. Cartridge also permits automatic threading of

the film into some microfilm readers with such function.

Rolls of microfilm with width of 16mm are commonly used for

filming correspondence, cheques, invoices and forms which are

of relatively small size such as B5 and A4. The wider 35mm

films are often used for microfilming larger documents such as

maps, newspapers, engineering drawings and records of

archival value that require clearer and higher image quality.

Roll Film

Cartridge

1 Microfilm in roll film format available commercially are commonly measured in imperial units.

5

b. 35mm & 105mm Aperture Card

Aperture card is made of a single frame of 35mm roll

film inserted into an aperture window in a card.

Aperture cards are primarily used for engineering

drawings. The larger 105mm film is sometimes used

for extremely large engineering drawings and maps.

The common size of an aperture card is 83mm x

188mm.

Aperture card with

35 mm film

c. Microfiche

Microfiche comes in different sizes. A typical microfiche is a

sheet of 105mm x 148mm microfilm on which a series of

images are arranged in rows and columns. A header is also

provided for human-readable identification. The number of

images that can be captured on a microfiche depends on the

reduction ratio. For example, 98 pages of A4 documents can

be stored on one microfiche with 7 rows x 14 columns at a

reduction ratio of 24X.

Microfiche format is most suitable for applications such as manuals, catalogue,

engineering files and micropublishing.

1.8.1 Microfilm Jacket

A microfilm jacket is a transparent, plastic or card-stock

carrier with single or multiple horizontal channels into

which strips of 16mm or 35mm microfilm are inserted.

With the use of a jacket, strips of film are protected and

easily organised into units of information similar to

microfiche. The films may be duplicated without

removing the jacket. New microfilm records can be

inserted into the jacket for information updating. Jackets

are widely used for correspondence, legal, customers and

insurance policy holder files.

1.9 Microfilm Hardware

The basic hardware of a micrographic system includes equipment for filming,

processing, quality inspection, duplication, viewing, making hardcopies and storage.

The minimum piece of equipment needed in an office to use microfilm records is a

microfilm reader.

6

a. Filming Equipment

Planetary and rotary cameras are used in source document

microfilming. The 35mm type planetary cameras produce

films with excellent image quality, as the records being

filmed are stationary and do not move through the camera.

It also allows filming of small size documents of different

thickness to large documents such as maps and plans.

However, the throughput rates of planetary cameras are

much lower than rotary cameras.

Planetary Camera

Rotary cameras are used with 16mm film and are designed for

applications where throughput is the primary consideration.

They are widely used in filming different types of business

records including correspondence, forms and computer

printouts. In filming, loose paper documents of up to A3 size

are fed into an opening of the camera and are transported past

a lens and a light source where images are recorded on

microfilm moving at a synchronised speed. It is the fastest

method of filming source documents. Filming speed can be

raised with the use of automatic feeding and stacking

attachments to the camera.

b. Processing Equipment

Microfilm processors develop, fix, rinse and dry film in an automatic process as the

film passes through the machine. Microfilm processors for silver gelatine film come in

different sizes, speeds and capabilities. Most of them can accommodate 16mm, 35mm

and 105mm film. They generally fall into two categories: tabletop and floor standing.

Tabletop processors are self-threading and can operate in normal

office lighting. They provide a convenient way to develop

exposed microfilm, particularly in a small-volume application,

and can meet permanent image processing requirements. Floor

standing (deep tank) processors, on the other hand, attain

excellent microfilm development consistency, achieve permanent

retention quality and maintain efficient use of development

chemical compared to tabletop processors.

Rotary Camera for 16mm Roll Film

Deep Tank Processor

7

c. Quality Inspection Equipment

Microfilm quality control equipment should be used to check developed film for image

quality. A high quality image is largely based on the complete capture of the

documents on film and the levels of image density and resolution.

Density is the light-absorbing or light-reflecting characteristic of the film.

Densitometer is the device used to measure if the film is too light or too dark for clarity

of reading and for production of paper copies.

Resolution is the ability of film to record fine details clearly. Microscope, eye loupe/

magnifier and inspection table/light box are typically used to check the clarity of

images of the developed film to ensure that acceptable levels of resolution are

maintained.

In addition, a methylene blue test kit is used to check the level of residual chemicals on

the film. Figure 1-1 shows the equipment required for conducting quality inspection.

The inspection procedures are explained in Chapter 5.

Figure 1-1 Quality Inspection Equipment

Inspection Table Inspection Station Eye Loupe/Magnifier

Densitometer

Microscope

Methylene Blue Test Kit

Light Box

8

d. Duplicating Equipment

Microfilm duplication is the production of microfilm copies from a microfilm master.

The master film is usually the camera original film. An intermediate master may be

created from the camera original film and be used as the printing master for further

duplication. Unlike original microphotography which is an optical process, microfilm

duplication relies on contact printing technologies using silver gelatine, diazo or

vesicular film.13

Duplicating different kinds of film for different

microforms often requires different types of duplicator.

There are machines which combine duplicating with

reformatting capabilities such as card-to-roll duplicators

and microfiche-to-roll duplicators.

e. Viewing and Printing Equipment

i. Microfilm Reader

Microfilm images must be magnified and projected for viewing.

Basic types of readers to magnify and view microfilm include

desk readers and free standing units. Availability of extra

lenses and accessories for viewing different microforms vary

according to models and user needs. Readers for 16mm and

35mm roll film require reel mounting and film threading.

Readers for 16mm cartridges are typically self-threading.

ii. Microfilm Reader-printer

Microfilm reader-printer combines the functions of a reader and

a copying machine to produce a hard copy of the documents.

For automated retrieval units, they are applicable to 16mm

cartridge film. They combine a reader or a reader-printer with a

device that automatically retrieves the desired image. In

retrieval, the operator enters the frame number of the image on

the keyboard and the film will then be advanced to the required

image. The film, however, must be image-marked (blipped) by

the camera during filming before it can be used in any

automated retrieval unit. Details on image indexing are

discussed in Chapter 5.

Duplicating Equipment

Microfilm Reader

Reader-printer

9

iii. Digital Microfilm Scanner-printer:

Digital microfilm scanner-printer supplements the function

of a microfilm reader with digital imaging and printing

technology. It scans microimages directly from the

microfilm and displays the images on the monitor of the PC.

The digitalised images can be processed and stored in

different media, including CDs, flash memory, and printed

out with the use of a printer. The images can be sent to fax

machines or to other PC users by E-mail. Figure 1-2 shows

the workflow of digital microfilm retrieval system.

Figure 1-2 Digital Microfilm Retrieval System

Digital Microfilm Scanner-printer

10

f. Storage Equipment

Microfilm storage cabinets, specialised

shelves and units of different

configurations are available from a

variety of manufacturers. Cabinets,

metal shelves and carrousels are

frequently used for housing roll film and

cartridges whereas trays and cabinets are

used for storing microfilm jackets,

microfiche and aperture cards. Further

information about microfilm storage

equipment can be found in Chapter 6.

Figure 1-3 summarises the workflow and the equipment used in source document

microfilming operation.

Microfilm Cabinet

Mobile Microfilm Storage System

11

Figure 1-3 Workflow in Source Document Microfilming

12

CHAPTER 2

Choosing Microfilming Applications

2.1 Microfilm Versus Other Records Media

Not many people like to use microfilm when they can afford to work with piles of paper.

Some may avoid the use of microfilm completely as they believe it is an outdated

technology. While paper and optical disk/CD may continue to have certain advantages

(and disadvantages), one should not overlook the many benefits of microfilming which

not only justify the applications but keep the microfilming industry going for decades.

Table 2-1 gives a brief comparison of paper, electronic and microfilm records.

Table 2-1 Comparison of Paper, Electronic and Microfilm Records

Factors Paper Electronic - Microfilm

Quantity stored Fair to poor Excellent Excellent

Visual quality Excellent Excellent to good Excellent to good

Durability Excellent to fair Good to poor Excellent to fair

Security Excellent to good Excellent to fair Excellent to good

File integrity Excellent to poor Excellent to fair Excellent to good

Legality Excellent Excellent to good Excellent

Retrieval Good to poor Excellent Good to fair

Transmission ease Fair to poor Excellent Good to fair

Duplication ease Good Excellent Excellent to good

Ease of maintenance Excellent to good Fair Excellent to good

Human-eye readability Excellent Poor Good

Familiarity of users with

system

Excellent Excellent Good

Costs of (re)production Good to poor Excellent to good Fair

13

2.2 Advantages of Microfilming

The advantages of microfilming are numerous. The following are the prime reasons for

the popularity of micrographic systems:

a. Storage Space Savings - Microfilm records typically save up to 95% of the space

occupied by paper originals. Using microfilm records to replace paper originals

helps reduce records storage requirement and operating costs.

b. Durability - Microfilming is a proven technology for storing records of long

retention period. When microfilms are properly produced, handled and stored, they

can have a life expectancy up to 500 years.

c. Preservation of Information Integrity - As documents are placed in their proper

arrangement in a fixed unalterable sequence and captured on film, they are most

likely to stay in correct order despite heavy and prolonged use.

d. Cost-effective Records Protection - Duplicate sets of film can be made and stored

off site cost-effectively. Microfilm is a popular storage medium for the back-up

copies of vital records.

e. Prolonged Durability of Valuable Original Records - With availability of the

microfilm copy, valuable original records can be retired from active use so that

damage and loss of information caused by constant or excessive handling can be

avoided.

f. Easy Access and Distribution - Light weight duplicates can be produced and

distributed easily.

g. Court Admissibility - If the filming, processing and disposal of records are

properly conducted, microfilm by law is admissible as court evidence.

14

2.3 Common Microfilming Applications

Common applications include newspaper-clippings, personnel records, accounts

receivable/payable, purchase orders, service records, reports and publications, health

care records, contracts, payroll records and income tax returns, etc. The list is virtually

endless. These applications are relevant to all B/Ds. While there are few paper work

situations where the application of modern micrographic techniques can be ruled out as

a way of improving information storage and access, there are limitations which

potential users should be aware of before deciding on conversion.

2.4 Limitations of Microfilm

Microfilm is not a cure-all. The technology in a basic application does not normally

bring dramatic improvement for the records system already in place. Microfilm should

not be expected to eliminate weaknesses such as poor file organisation or indexing in a

recordkeeping system. Depending on individual applications and circumstances,

microfilming may have the following limitations:

a. Microfilming requires labour, equipment and supplies. For microfilm users, a

microfilm reader is required for viewing the images and a microfilm reader-printer

for the production of hard copies.

b. Physical conditions of records have to be good for microfilming.

c. Microfilm records are mostly not updatable except for the use of updatable

microfiche technology.

d. Durability and usability of film is governed by many factors such as the quality of

film used, proper processing control, appropriate storage condition and handling.

e. User resistance may be encountered for those who are not familiar with the

microfilm equipment.

2.5 The Choice of Microforms

The basic microfilm formats should be understood clearly and considered, as the

selected format of a micrographic application can greatly facilitate the use of the

microfilmed images. Table 2-2 summarises the advantages and characteristics of

various microforms.

15

Table 2-2 Characteristics of Various Microforms

Microform Characteristics Application Costs

35mm Roll Film

Excellent image

quality and file

integrity

Archival and/or

oversized records Expensive

16mm Roll Film

Good to fair image

quality, high speed

production and

excellent file

integrity

Business

correspondence,

invoices, cheques,

cards and forms

Inexpensive

35mm Aperture Card

Insertion of single

frame of 35mm roll

film into aperture

window; having the

same image quality

as 35 mm roll film

Large engineering/

architectural

drawings and maps

Expensive

Microfiche

Sheet of microfilm

containing a series of

microfilm images

and may be

updatable; good to

fair image quality

Manuals, catalogues,

indexes and finding

aids

Inexpensive

Microfilm Jacket

16/35mm film strips

inserted into

transparent plastic

carrier, allow

information updating

Correspondence

files, press cutting

files and customers

and policy holder

files which are

required to be

updated

Expensive

16

2.6 Factors to Consider in Microfilming Conversion

Microfilming all types of records is not cost-justifiable. Some types of records such as

fragile documents and records with colour variations or illustrations are difficult or

even unsuitable for microfilming as silver gelatine microfilm cannot record the colour

information. Moreover, blurred copies of records do not microfilm well. Defects on

the original documents may distort the information on the microfilm. Decisions as to

what should be microfilmed must come from careful consideration of the following:

a. Physical Characters of Records to be Microfilmed - Records in loose formats are

much easier and faster to microfilm than bound volumes. Depending on the

resolution characteristic of the camera used, records with very small characters may

not be clearly captured on microfilm.

b. Overall Quality of Documents - Records must be legible and in good physical

condition to permit clear capture of image and withstand handling during

microfilming. Torn pages require costly and time-consuming pre-filming

preparation work before they can be microfilmed properly.

c. Retention Period of Records - Usually it may not be cost-effective to microfilm

unless a record is to be kept for at least 7 years.

d. Volume of Records - Microfilming is more cost-effective if it is applied for large

quantity of records because it involves investment in equipment and supplies.

e. Update Requirements and Frequency - Records which require constant updating

are not generally suitable for microfilming.9

f. Access Frequency and Number of Copies Required - These affect indexing

requirements, the choice of equipment and overall costs.

g. Inactive Status of Records - Microfilm only closed records unless you are willing

to invest in a computer assisted retrieval system.

h. Legal Requirements - Records required as court evidence should be microfilmed

rather than converted into other media of which legality is not clear.

i. Quality Requirements - Users should not ignore the importance of image quality

characteristics of different microfilm formats. If the microfilm is intended for

preserving the information of the source document for a long period of time, high

image quality is a must.

17

2.7 Where to Microfilm

The fundamental choice is to decide whether the work should be done in-house or

through outsourced service by external service providers.

2.7.1 In-house Filming

The acquisition of all the equipment and supplies, personnel and space required for a

microfilming operation can be very expensive and specialised. But the advantages

include better security and confidentiality, availability of records in emergency during

filming, and better quality control.

2.7.2 Filming by External Service Provider

Since a service provider is a commercial microfilm business, employing its service may

offer the distinct benefits of expertise and experience, cost savings in production

equipment, and avoidance of specialised personnel of an in-house operation. However,

service provider’s work may have problems in terms of quality deficiencies, slow

turnaround time, interruption of office routine by the activity of the service provider,

and loose security control of records.

If a B/D employs an external service provider to carry out its microfilming programme,

the B/D concerned must be satisfied that the operation of the service provider provides

adequate security for the documents, and adequate documentation and procedural

control to ensure that the produced films are usable, durable and court admissible as

required. There should be full documentation which describes the types and categories

of records to be microfilmed, the microform to be used, the indexing techniques, the

appropriate reduction ratio of each application, specifications of microfilming and

quality control procedures, and technical standards to be used. The service provider’s

services should be reviewed from time to time and the microfilm output should be

checked systematically and regularly.

2.7.3 Microfilming by the Government Microfilm Centre

The Government Microfilming Service Centre of GRS was set up in April 1997 to

provide centralised microfilming services for B/Ds. It was renamed as the Government

Microfilm Centre (GMC) in July 2004. The benefits of centralised filming are a

combination of those enjoyed by in-house filming and using a service provider. A

centralised programme whose sole task is to microfilm is more likely to provide quality

work than those where micrographics is merely one of the many functions. Moreover,

it will be able to provide a broader range of services than what can normally be

supplied within an office itself. Further, staff members of GMC are full time trained

staff, their expertise and efficiency should result in cost savings and better quality work.

18

Finally, records security and confidentiality can be better assured. GMC’s functions

and services are detailed in Chapter 3.

2.8 Checklists for Conversion

Regardless of who will conduct the microfilming, the user and the microfilming party

should be clear about the terms under which the microfilm will be provided and their

respective responsibilities. In particular, the following issues should be considered:

The quantity of records to be microfilmed;

The price to be paid if that applies;

The responsibilities and the extent of document preparation;

The responsibilities for identifying the records to be microfilmed;

The types of microform to be used;

The types of film and reduction ratios to be used;

Film indexing requirement and preparation;

The filming and processing standards required;

The number of film copies required;

The custody or ownership of the master negative;

Post-filming source documents preparation/arrangement; and

Records disposal requirements for both source documents and the microfilm records.

19

2.9 How to Start a Microfilming Project

A microfilming project must be accessed and weighed in terms of its costs and benefits.

To ensure the economical and operational feasibility of the project, a detailed system

analysis should be conducted for the planning, design, evaluation and implementation

of the proposed application.

The following work steps are suggested for the system analysis:

a. Determine user needs;

b. Examine documents and data files that will serve as input into the micrographic

system;

c. Select the appropriate microform;

d. Determine the records retention period, film quality, microfilm standards

requirements and number of copies to be produced;

e. Plan for microfilm production capabilities including equipment specifications,

workflow and training;

f. Gather information about the requirements and costs of in-house production,

contracting out to a service provider and using the microfilming service of GMC;

g. Plan for microfilm retrieval and storage equipment and facilities;

h. Prepare system cost estimates and cost justification analysis for equipment and

furniture costs, supplies, facilities, personnel time and consultants’ assistance where

applicable; and

i. Consider a “test run” of the planned conversion process in order to decide on the

procedures needed and to determine how long the entire conversion will take place.

A comprehensive and accurate system analysis is critical for a successful microfilming

application. B/Ds requiring assistance are welcome to contact GRS for information and

advice. 23

20

CHAPTER 3

Government Microfilm Centre (GMC)

3.1 Establishment of GMC

Arising from a feasibility study by the Records Management Strategy on the need of

establishing centralised microfilming facilities within the Government, the Government

Microfilming Service Centre was established in April 1997 under GRS. It was

subsequently renamed as GMC in July 2004.

3.2 Functions and Services of GMC

GMC aims at providing customer oriented microfilming services for B/Ds where

substantiated requirements are identified. GMC adopts ANSI/AIIM standards in its

microfilming operations to ensure the usability, durability and court admissibility of the

microfilm records it produces. GMC’s functions and services include the following:

a. Technical Advice - To provide technical advice and information on microfilming

procedures and systems including assistance in indexing design to facilitate

microfilm retrieval.

b. Filming of Source Documents - To provide filming services on 16 mm silver

gelatine polyester roll film according to the needs and requirements of B/Ds.

c. Processing and Duplication - To provide film processing and duplicating services

on silver gelatine film for B/Ds.

d. Quality Control - To conduct quality control including laboratory tests on the

microfilm produced.

e. Arrangement of Records and Microfilm Delivery - To assist B/Ds in arranging

the delivery of source documents to GMC for microfilming; and to deliver

processed microfilm to B/Ds.

f. Storage Facilities for Microfilm - To provide microfilm storage for the master

microfilm in accordance with international standards.

g. Coordination of Records Disposal - To coordinate with Records Management and

Administration Office and the Public Records Office to dispose of the filmed source

documents after quality inspection of the microfilm copy.

21

3.3 Records Filming Criteria of GMC

GMC provides free microfilming services for B/Ds primarily on 16mm silver gelatine

roll film format. The selection criteria for filming are as follows:

a. Size and Weight

i. Document should be in A4 size while small quantity of records from A6 to A3

may also be accepted.

ii. Paper in each document/folder/batch should preferably be of uniform size and

weight.

b. Paper Format

Documents should be in loose sheets. Small quantity of other formats such as books,

journals, computer printouts may be accepted.

c. Legibility and Paper Condition

i. Original records (source documents) should be of reasonable legibility.

ii. Imperfections on records such as stains and obliteration that affect legibility may

not be accepted.

iii. Paper should be legible with little variations in the colour of paper and ink used.

iv. Fragile documents and documents with torn pages and/or corners may not be

accepted.

d. Records Integrity

Records used as legal evidence must be the original/official copy produced from

official transactions in natural accumulative order. Any missing pages or file-

weeding/culling prior to filming must be specified.

e. Retention Periods

B/Ds must clear the records retention and disposal schedule for the records to be

filmed with the Records Management and Administration Office and the Public

Records Office. Records should preferably be of retention period of at least 7 years.

f. Requirement for Updating

Records should require minimum or no additions, deletions or alterations.2

22

3.4 Procedures in Using GMC’s Services

B/Ds interested in using GMC’s services should follow the procedures below:

a. B/Ds should forward request for microfilming services to GMC using form GMC 1

(Appendix A).

b. If requirements for microfilming application are substantiated, GMC will assist the

B/D in clearing the records disposal requirements with the Records Management

and Administration Office and the Public Records Office.

c. Technical filming details and indexing requirements will be specified by GMC in

consultation with the B/D.

d. The B/D should arrange to send records to GMC at its own cost.

e. Records to be microfilmed must be packed in filming order. A filming list showing

the exact filming order should be attached using form GMC 2A & 2B (Appendix B).

f. The records will be microfilmed, checked, boxed, indexed, labelled and delivered to

B/Ds for inspection together with the standard memo form GMC 3A (Appendix C).

g. The B/D should check the quality and the accuracy of the microfilms delivered, and

confirm with GMC acceptance of the microfilms using the standard memo form

GMC 3B (Appendix D). If the B/D is not satisfied with the microfilms and requires

retake, it should make a request within the specified period by GMC after receipt of

the microfilm copy using form GMC 3B (Appendix D).

h. GMC will confirm with the B/D to undertake suitable disposal action for the source

documents according to their records retention and disposal schedule(s).

i. GMC will provide an additional duplicate microfilm copy for the B/D on a need

basis.

j. The B/D will be responsible for purchasing its own microfilm reader or reader-

printer and other micrographic system hardware.

3.5 Pre-filming Preparation of Source Documents

Document preparation is one of the most important components of a successful

micrographic project. Attention must be given to this crucial step to ensure that

efficient and quality filming can be achieved.

Records are often microfilmed in the order in which they were originally created and

maintained. Unless a random file arrangement is used, special care should be taken to

23

retain that order. Before records are filmed by GMC, B/Ds should be responsible for

undertaking the following preparation procedures:

a. Inspect original documents for illegible area or stains;

b. Remove clips, staples, rubber bands and fasteners from the source documents;

c. Repair or photocopy torn and damaged documents. Use frosted or invisible sticky

tape to repair rips and tears;

d. Flatten rolled, folded and creased documents;

e. Identify illegible documents and insert a transcription of the record where applicable;

f. Identify missing pages or documents and insert a document missing target stating

“Missing Page(s) at Time of Filming” into the records (Appendix E);

g. Arrange documents in sequential filming order facing the same heading direction;

and

h. Pack documents in bundles with package labels, place in numbered boxes and

deliver to GMC.

3.6 Request for Digitised Copy of Microfilmed Images

In addition to the microfilm copy which is

the default deliverable of a typical GMC

project, the B/D can also request a

digitised copy of the microfilmed images.

The purpose of the digitised copy is to

facilitate easy access to the document

images. The digitised copy will be in

Portable Document Format (PDF) file

which is accessible in most computer

environments. Depending on the set-up

of the network environment, the digitised

copy can be accessed by more than one

computer at the same time. Unlike the

microfilm copy, GMC would not keep any back-up of the digitised copy and it is the

responsibility of the B/D to properly protect the digitised copy from any accidents and

disasters (such as data corruption, storage media deterioration and technological

obsolescence) that may arise in the future.

Despite the high resolution and image quality of today’s digitisation technology, the

digitised copy produced from scanning the microfilm copy of the source documents can

High-speed Microfilm Scanner

24

only capture the source document images in black-and-white, all colour information, if

any, in the source document will be lost. Should the B/D require colour digital images

of the source document as in a typical digitisation project, they should seek service

from external service providers.

Figure 3-1 Production Cycle in GMC

Production Cycle in GMC

Source

Document Filming by

Rotary Camera

Filming by Planetary Camera

Processing by Deep Tank Processor

Roll Film Product

Standard Storage Indexed Final

Product Methylene Blue Test

Duplication Quality Inspection

25

CHAPTER 4

Production Filming and Processing

Control

4.1 General Requirements

Microfilming should be undertaken in such a way to ensure the full legibility of the

resulting microform. This involves using the correct balance of lighting and exposure

to achieve optimum density and resolution, and selecting the reduction ratio appropriate

to the sizes of the documents to be microfilmed and the line densities of their text.

Whether documents are microfilmed in-house, by external service providers or by

GMC, appropriate filming standards and proper filming procedures must be established

and followed to ensure consistent quality of the microfilm output.

4.2 Filming Archival Records, Permanent Records and

Records for Legal Acceptance

Microfilm applications that capture records of archival/permanent and legal value

should meet the requirements listed below to ensure film life and long term

preservation of the information contained therein.

Sections 39 and 40 of the Evidence Ordinance (Cap. 8) stipulates that microfilm of

government and business records are court admissible provided they are produced as

permanent records and the source documents are disposed of afterwards. Thus the

following should be noted and adhered to:

a. Silver gelatine polyester film is the required film type for generating microfilm

records of archival/permanent value and records which require legal admissibility.

b. Conventional wet processing is recognised as the most stable processing method to

achieve microfilm permanence.

c. All films including the microfilm master (also known as camera microfilm or first

generation of microfilm), duplicate master (also known as print master or second

generation of microfilm) and reference copy (also known as viewing copy or

working copy is printed from the print master) should be inspected thoroughly to

ensure image quality, stability and usability.

26

d. The microfilm master should be stored in proper storage conditions at all times to

ensure that the information stored on microfilm is not distorted, retrievable and

usable in the future.

e. To ensure longevity and court-admissibility of the microfilm records, there should

be clear and well-documented operating procedures in document preparation,

filming, processing, inspection, duplication, storage and disposal. Further

information concerning microfilming standards and requirements for records with

legal implications is given in Chapter 6.

4.3 Proper Microfilming Procedures

All stages in the microfilming process must be carried out under controlled conditions.

The purpose is to ensure both microfilm quality and the credibility of the microfilming

application/programme as well as to assist the responsible B/D to prove, if required,

that the microfilmed image is a true reproduction of the original. To achieve these ends,

whether or not the records to be microfilmed are of archival, permanent or legal value,

the following microfilming guidelines and procedures are recommended:

4.3.1 Preparation before Microfilming

a. Only trained operators who understand the capabilities of the equipment used and

are familiar with the required operating procedures are allowed to microfilm

documents.

b. Operators should perform equipment calibration and maintenance tasks regularly.

c. When documents arrive at the camera, they should be checked for the correct order

with all the page headings in the same direction.

d. Insert and check targets (Appendix E) in the correct place for the proper filming

order. Certain basic targets should be filmed on every roll to assure legality, and to

aid in measuring film quality and identifying film contents. Suggested target

filming order is as follows:

Density

Target

(White

Board)

Start of

Roll No.

Statement

of

Certificate

Resolution

Test Chart

Titleboard

Text

27

Text

Titleboard

Resolution

Test Chart

Statement

of

Certificate

End of

Roll No.

e. Additional targets such as indexing target, reduction ratio target, correction target

and retake target should be filmed where needed (see Appendix E for samples).

f. Conduct step test to determine the correct exposure setting in order to achieve the

desired film density. According to ISO and ANSI/AIIM standards, the

recommended densities for microfilm images are divided into 4 groups. They fall

between 0.75 and 1.30 in negative appearing silver gelatine microfilm that has a

minimum or clearest density of the film not exceeding 0.10. Table 4-1 gives the

density range for different conditions of documents.

Table 4-1 Density Table

Group Description of Documents Density

1

High quality, high contrast printed books and

periodicals, black type face, fine-line originals, black

opaque pencil writing, and documents with small,

high-contrast print.

1.00 - 1.30

2

Pencil and ink drawings, faded and very small print

such as footnotes at the bottom of a printed page,

scenic cheques, documents with printed pictorial

images, and newspapers.

0.90 - 1.10

3

Low-contrast manuscripts and drawings, graph paper

with pale, fine-coloured lines, letters typed with a

worn ribbon, and poorly printed, faint documents.

0.80 - 1.00

(1:24 reduction or less)

4 Very low contrast (worst case) documents can require

extremely low background

0.75 - 0.85

(1:24 reduction or less)

Source: ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents.

28

g. Determine the image orientation. Roll film is generally produced in 4 formats for

arranging the images:

(1) simplex-comic orientation,

where the images are filmed

side by side, like a comic strip;

Simplex-comic orientation

(2) simplex-cine orientation where

a single line of images is

continuous, like motion picture

film;

Simplex-cine orientation

(3) duplex mode, where both sides

of a document are filmed

simultaneously side by side;

and Duplex mode

(4) duo mode, where the images

run up one half of the film and

back down the other half.

Duo mode

h. Determine the image polarity (negative or positive-appearing images). Negative-

appearing image is a photographic image in which the lines and characters appear

light against a dark background. Positive-appearing image is a photographic image

in which the lines and characters appear dark against a light background. Figure 4-1

shows the difference between negative- and positive-appearing images.

29

Figure 4-1 Negative and Positive Images

Negative Image

Polarity

(on film & screen)

Positive Image

Polarity

(on film & screen)

(hardcopy) (hardcopy)

Negative images have higher contrast, cause less eyestrain and generally produce

higher-quality printouts than positive images. Positive images cause greater

eyestrain.

i. Select an appropriate reduction ratio of the microfilm which is the number of times

the size of the original document is reduced to form the image on microfilm. For

example, a reduction of 24:1 means that the image on the microfilm is 1/24 the size

of the original document.

The reduction ratio to be used in a microfilm system is determined by the size and

contrast of the original documents, the size of text characters, the microfilm formats

chosen, and the type of camera used for filming. User should determine the desired

image quality and the reduction ratio that can achieve this quality. In general, lower

reduction ratios provide higher image quality and larger images. A larger image is

more tolerant of poor-quality original documents and resolution loss. Thus, a lower

reduction ratio is preferable to a higher reduction ratio. The following reduction

ratio chart showing the recommended reduction ratio for different document sizes is

a useful reference.

30

Source: ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents.

4.3.2 Actual Filming

a. To film, load the microfilm in the camera unit according to the manufacturer’s

instructions for film direction. The emulsion side must be facing the camera lens for

images to be captured on the film.

b. After film loading, create a film leader by advancing the film between 600mm and

900mm before filming the beginning targets to prevent fogging on the film images.

c. In addition to the film leader, a minimum length of 1000mm film should be left at

the beginning of the roll to accommodate for some reader machines with automatic

threading capability. Where applicable, a minimum length of 140mm of film should

be reserved for the methylene blue test. The latter should be conducted within 14

days after processing to ensure the film is washed properly. Details of the test are

given in ISO 18917:1999.

d. When using a planetary camera, documents should be filmed flat to avoid losing

information to shadows or creases. Where necessary, use glass plates or clear

31

plexiglass to achieve desired results. The entire documents should be placed in the

photographic field of the camera. For oversized documents, they shall be

microfilmed in sections with a minimum of 100mm overlap of the original material.

e. When using a rotary camera, the leading edge of documents must be as straight as

possible. Trimming should be minimal so that no information is lost. Heavily taped

documents should be fed through manually.

f. The integrity of the original records and the order of the record collection should be

maintained during filming. Microimages of the records should be arranged,

identified and indexed so that any individual documents or components of the

records can be located easily.

g. Occasionally a filming mistake may be noticed during filming operation and may be

corrected on the spot, a film correction target must be used. This is to ensure that

the original continuity of the documents has been maintained during refilming. If a

filming error is found after the film is processed, amendment should be filmed with

an amendment target and spliced to the start or the end of the roll it belongs to.

h. When the end of roll alarm sounds, be sure to wind all the film onto the take-up reel

before unloading the camera. This film trailer prevents fogging in loading the film

into the processor.

i. A minimum length of 700mm film should be provided at the end of the roll as a

reader/duplicator trailer so that the last image can be viewed or duplicated steadily.

4.3.3 Filming Sequence

Filming should be conducted in the following suggested sequence:

Leader

Space

Density

Target

Start of

Roll No.

Statement of

Certificate

Resolution

Chart

Title

Board

Space

Appropriate

Targets when

needed

Space

Documents

being filmed

Space

32

Title

Board

Resolution

Chart

Statement of

Certificate

End of

Roll No.

Trailer

Methylene

Blue Test

Area

4.4 Film Processing

Processing of different types of film requires different processors and procedures. This

manual deals mainly with silver gelatine film. It involves the use of a processor, a

mechanical device, which provides the exposed film with a series of chemical and

physical treatments to produce photographic images.

4.4.1 Processing Elements

Conventional wet processing involves the following elements:

a. Film development which causes the exposed image to appear;

b. Stop bath or rinse which arrests development, prevents stains and helps preserve the

life of the fixing bath;

c. Fixing which removes all undeveloped silver halide from the film emulsion layer;

d. Washing which removes residual processing chemicals from the film; and

e. Drying which removes moisture from the film. Drying needs to be carefully

controlled to ensure the film is not damp or brittle.

4.4.2 Choosing a Processor

Processing affects image quality and whether the residual processing chemicals are

properly removed from the developed film. The major factors include temperature,

strength of the chemicals used and the processing speed. The following should be

considered in choosing a processor:

a. Consistent density of film from roll to roll and day to day;

b. Uniform density;

33

c. Complete edge to edge processing;

d. Thorough washing to meet ANSI or ISO specifications on residual processing

chemicals level;

e. Free from scratch, dust, water spots and physical deformation; and

f. Precision temperature control that should not exceed ±3°C from the temperature

established as optimum for the film and processor.

4.4.3 Processing Control

To achieve quality results, processing control should be established where processor

should be monitored regularly by using processing control strips to ensure consistent

quality. The strips should be used at the start of processing each day, after changing

chemicals and three or four times a day if a high volume of film is being processed.

34

CHAPTER 5

Microfilm Inspection, Duplication,

Indexing and Retrieval

5.1 Quality Control Procedures

Microfilm must be inspected after processing to ensure that it meets the established

standards for complete capture of image, clarity, usability and durability. Such flaws as

blurs, poor resolution or density and photographic streaks must be detected immediately

because they are often caused by equipment failures. They must be corrected promptly

so that such defects will not be repeated in other films. In conducting film inspection,

the following practices are recommended:

a. The microfilm after processing should be inspected as soon as possible to ensure

technical specifications are met.

b. Film inspection should include measuring (i) resolution by a microscope and

specialised resolution chart, (ii) density by a densitometer and (iii) amount of

residual processing chemicals on the film by methylene blue test. The film should

also be examined for image legibility.

c. Wear clean, lint free white cotton or nitrile gloves to handle microfilm with care.

Do not leave the microfilm exposed to overhead lighting or direct sunlight which

will cause fading of the image.

d. Conduct inspection in minimum ambient light and avoid fluorescent lighting which

is notorious of significant ultra-violet light content.

e. Visually inspect the microfilm for the following by using a hand-held photographic

measuring magnifier (6X to 15X loupe) and a light box while manually advancing

the film on rewinds:

- Evenness of focus and density across the frames;

- Sharpness and clarity of the images;

- Proper titling information;

- Proper targeting of faults and any omission;

- Proper sequence of documents and absence of any unintentional omission;

35

- Absence of mechanical damage such as scratch resulting from faulty camera or

processing equipment.

f. Prepare and maintain an inspection report to note results of the quality check of each

roll of film. The inspection report shall be signed and dated. Samples of the

inspection report and defects guide are attached in Appendices F & G.

g. Use a quality 100X magnification microscope to check the smallest clear pattern

shown on the filmed image of ISO Resolution Test Chart. This pattern number’s

numeric value multiplied by the reduction used is the resolution of the film. For

example, if the pattern number is 5.0 and the reduction ratio is 24X, the resolution is

120 lines/mm (5.0 x 24X = 120). Values below 120 lines/mm indicate substandard

resolution. The resolution of each roll of film must be estimated.

For the first generation of microfilm, the quality index at level 52 should be aimed at

as the minimum. Detailed discussion of the Quality Index can be found in

ANSI/AIIM MS 23-2004. Samples of resolution test chart are attached in

Appendices H & I.

Resolution Test Chart

(NOTE: This chart is for illustrative purpose only and cannot be used for test purpose.)

Resolving power = Pattern Number x Reduction Ratio

2 Quality index at level 5 means the image quality is considered acceptable because on the final generation, all number and letter characters are legible. For more details on quality index, please refer to pages 46 to 51 of ANSI/AIIM MS 23-2004.

e.g. Resolving power Pattern No. Reduction

Lines/mm Lines/mm Ratio

113 7.1 16X

120 = 5.0 X 24X

135 4.5 30X

36

h. Measure the background and image density of the film with a densitometer. There

should be general check of density evenness across a few sampled frames and

between frames. The density of the images on a microfilm roll will vary depending

on the type, age and condition of the original documents. Some poor quality, low

contrast documents may require a density range of 0.75 to 1.00 while high contrast

prints could be filmed at 0.90 to 1.30. The maximum allowable difference between

highest and lowest density across a document of even background or between

different documents of identical background should be +/– 0.08 on the density scale.

If wide density variations occur, a retake of film will be necessary.

i. The excessive amount of residual processing chemicals (thiosulphate or fixer) left

on microfilm will create blemishes and may adversely affect the images. Thus

methylene blue test should be conducted to ensure that the microfilm is free from

this condition. Details regarding the test are found in ISO 18917:1999. The

maximum thiosulphate ion concentration allowed is 0.014 grams/square metre. The

test shall be conducted within 14 days after processing of film. If the producer is an

external service provider, it is advisable for the test to be conducted by an

independent agency and relevant records be kept. All microfilm rolls that are found

to have too high residual processing chemicals concentration must be re-washed

until they meet the standard for preservation.

j. Completely unsatisfactory roll of microfilm should be rejected and refilmed all over.

When individual frames of microfilm are defective, the related items/pages should

be refilmed and the new film after rechecking should be spliced with the use of an

ultrasonic splicer at the beginning or the end of the film with appropriate targets to

instruct the viewer where the retaken images should appear in the document. Not

more than three splices (six cuts) are allowed in a roll of film. The correct practice

in splicing the correction is to include both the two images or frames before and

following the correction in addition to the correction itself. There should not be any

splices between the technical targets and the first or the last 10 images on a roll.

k. All images should preferably be visually inspected. Alternatively, the film should

be checked every 3 metres for any major or minor defects to determine if retakes are

necessary. A minimum of 10% visual inspection of randomly selected microfilmed

images should be performed.

5.2 Microfilm Duplication

The original camera film is usually considered the preservation copy for the

information the original documents contain. As silver gelatine film can be easily

scratched with use, the creation of a microfilm duplicate for information retrieval and

distribution is necessary to protect the preservation copy.

37

5.2.1 Different Generations of Microfilm

The original camera film is considered the microfilm master and each duplicate is

considered a generation of the film. The master is the first generation, the duplicate

made from the master is the second generation and the duplicate produced from the

second generation duplicate is the third generation and so on.

Each successive generation of microfilm loses resolution or image clarity which may

cause legibility problems. Thus duplicates for distribution and retrieval should be made

from the master or the second generation film to achieve consistent legible quality.

With good quality control practices during microfilming and processing, duplicates

from the master and the second generation film should be of sufficient quality to ensure

complete image legibility.

One fundamental strategy of preservation microfilming is to produce three generations

of each microfilm. The first generation master is given long term secure storage while

the second generation is used for generating duplicates and the third generation as the

working or reference copy.

5.2.2 Factors to Consider in Making Film Duplicate

a. The master camera film should never be used for viewing. Its only purpose is to

produce second generation copies, normally called intermediate masters or printing

masters. The latter is used for making further copies or as reference copies.

b. Direct duplicating film (silver gelatine) is recommended to create a printing master.

Reference or duplicate copies can be created using silver gelatine, diazo or vesicular

film. The type of duplicate will depend on the quality and polarity requirements of

the reference copy as determined in the information and system planning study.

c. Diazo film duplication produces a polarity maintaining copy, that is a positive

appearing master produces a positive appearing duplicate of diazo microfilm. In

contrast, the vesicular film duplication will produce a negative appearing duplicate

from a positive appearing master. Though not easily damaged with use, both diazo

and vesicular film are sensitive to elevated temperature and light, and may lose up to

40% of the master resolution in third generation duplication. They are generally

selected because of their lower cost and when permanent storage of copies is not

required.

d. Duplicate microfilm should be subject to the appropriate chemical tests and physical

checks though detailed frame to frame inspection is not often necessary if the

quality of the master is assured, its density has been measured and the duplicator is

working properly.

38

5.3 Microfilm Indexing and Retrieval

Conversion of paper-based files to microfilm involves an analysis of the indexing

system used, an evaluation of that system and its suitability for microfilm organisation

and retrieval.

Applications that involve well organised, logically arranged paper records can be

sequentially replicated on microfilm, and the original arrangement of the paper files can

be retained. Microfilming random or unorganised records presents a greater challenge.

If the records lack organisation due to ineffective records management, they have to be

put into order to facilitate identification for indexing and retrieval.

Accurate indexing of microfilm is thus necessary for both identifying the contents of

the film and for locating specific images.

5.3.1 Different Types of Microfilm Indexing and Retrieval Methods

Microfilm indexing methods, including manual and automated retrieval techniques, are

used to facilitate the location of desired document images. Basic format indexing

includes labelling the roll film boxes with identification information such as roll

number, titles and dates of the records and documents filmed on the roll, dates of

filming and the owner or custodian B/D(s) of the records. All roll film indexing

methods must include some type of written or computerised index that indicates the

specific roll number and location of segments or individual images on the film. Roll

film indexing methods include the following:

a. Flash Target Indexing

Flash target indexing involves filming a

large target between the documents to

assist the viewer in determining the

breaks in the film file. The flash target

may be letters or letter combinations for

alpha sequence filming, dates or years

for chronological sequence filming,

numerical sequence filming, etc.

39

b. Sequential or Frame Number

Sequential frame numbering involves

filming a sequential number on every

film image frame. The number may be

placed on each document either

manually or with a document imprinter,

or placed adjacent to each frame as the

documents are filmed.

c. Image Mark (Blip Mark) Indexing

Image mark (blip mark) indexing involves filming a camera-generated mark under each

image frame. The mark is counted by a photoelectric cell on the viewing equipment to

retrieve the required image. This indexing method is used in association with

sequential frame number indexing for developing a workable retrieval system. The

image marked film can be retrieved using either a calculator-style keypad retrieval

device on the microfilm viewing equipment or fully automated Computer Assisted

Retrieval system (CAR). Sample of blip mark indexing is given in Figure 5-1 below:

Figure 5-1 Blip Mark Indexing

d. Odometer Indexing

Odometer indexing indicates the

distance of each image from the

beginning of a roll of film to a

particular document on the film. It

involves measuring inches or

millimetres along the length of the film.

An index is prepared by examining

processed images on a microfilm reader

or reader-printer equipped with an

odometer.

40

e. Photo-optical Bar Code Indexing

Bar code indexing is based on optical

codes recorded on the film to represent

a numerical identifier. The bar code is

either used directly on the film for

image retrieval or is scanned from the

document during filming to create a

computer index to the image location.

f. Computer Assisted Retrieval (CAR)

CAR system is a method of microfilm retrieval using a computer index to locate a

specific index by referencing location identifiers (roll and frame number). In the

filming stage of microfilm production, the CAR system requires the camera to put

marks (computer encoded information) together with the document images on a roll of

16mm microfilm which are then inserted into a cartridge. In addition, there are other

essential components for image retrieval as follows:

- a database index containing reference to an image identifier;

- a roll number location and a frame number location; and

- a computer for access to the database and a cartridge reader or reader-printer with

appropriate image mark level recognition which is either database driven or has a

input device for entering frame number.

CAR is the fastest retrieval method available for roll film format and the system can be

very simple or as sophisticated as necessary to meet high level, complex retrieval needs.

The easiest method of establishing a CAR system is to buy a packaged system. It is

also possible to establish a CAR system using simple integrated components which may

include existing personnel computer access and/or purchased software. If in-house

programming is available, the cost of establishing a unique CAR program will be

reduced. 41

41

CHAPTER 6

Microfilm Maintenance

6.1 General Requirements

Proper handling and storage of microfilm are important to ensure that the film will last

for the life span it is intended. Although working or reference copies of microfilm need

not be stored and handled under the stringent conditions set for the care of the master

film or the print master, reasonable care in handling will extend their usable life.

6.2 Proper Microfilm Handling

a. The master negatives and intermediate masters intended for making further copies

can be damaged through improper handling and they should be handled as

infrequently as possible and always with care. They must not be handled with bare

hands. Always wear gloves in handling microfilm especially for master microfilms.

b. Microfilms should be handled only by their edges and equipment should be clean

and well maintained.

c. Microfilm should not be left on the reader machine exposing to overhead lighting or

direct sunlight because they cause fading of the images, especially for prolonged

period of time.

d. Roll film should be wound tightly but not under extreme tension on spools or reels.

The film should not be wound beyond the edges of the flanges of the spools or reels

and may be secured by a thin card collar tied with string. Rubber bands must not be

used to fix loose ends.

6.3 Proper Microfilm Storage Conditions

a. Microfilm will decay if they are stored in unsuitable or fluctuating environmental

conditions, especially under high temperature and high relative humidity level.

b. Microfilm should be stored in conditions specified in ISO 18911:2010 Imaging

materials - Processed safety photographic films - Storage practices.

42

c. Generally speaking, for long term storage of polyester based silver gelatine films,

temperature should be 13°C ± 2°C and relative humidity ranged between 30% and

40%. The maximum temperature should not be higher than 21°C.

d. For medium term storage of polyester based silver gelatine films, the maximum

temperature can be up to 25°C, and relative humidity can be allowed to fluctuate

between 30% and 60%. To avoid mould growth, the films should never even for a

short period be stored in a relative humidity above 60%. Table 6-1 summarises the

storage conditions for microfilm.

Table 6-1 Storage Conditions for Microfilm

Temperature for the storage of silver gelatine films

Long-term Storage (Life expectancy of 100 years+)

13°C ± 2°C Maximum temperature without risk of damage to the film is 21°C

Medium-term Storage (Life expectancy of 10 years)

25°C Normal maximum peak temperature not to exceed 32°C

Relative humidity for the storage of silver gelatine films

Long-term Storage (Life expectancy of 100 years+)

Silver

gelatine 30-40% (polyester base)

Medium-term Storage (Life expectancy of 10 years)

Silver

gelatine 30-60% (polyester base)

e. Viewing or working copies of film should also be preserved in a stable and

controlled environment if their continued usability is to be guaranteed.

f. The storage environment should also be free of dirt, dust and pollutants, especially

sulphur dioxide fume from automobile emissions, power stations or plants which

consume fossil fuels.

g. When environmental conditions in the area in which microfilms are to be copied or

consulted cannot be maintained at the same levels as the storage area, the

microfilms should be allowed to readjust to new conditions before use.44

h. A representative sample number of the microfilm rolls in the storage should be

inspected at regular intervals. Deterioration should be noted and the cause of

problems should be ascertained. Once deterioration has been identified, copy

43

should be made from the roll of deteriorating film, if no master film is available and

the roll of deteriorating film should be removed from other stock.

i. Diazo and vesicular films should not be stored near silver gelatine films as they give

off gases harmful to the latter.

6.4 Microfilm Storage Equipment and

Supplies

a. Microfilm should be stored in appropriate cabinets or shelves

made of non-corrosive metal and treated with chemically

inert coating. Wooden or plastic cabinets should not be used.

b. Microfilm reels, spools and containers should be constructed

of inert and non-corrosive material free from acidic, oxidising

and reducing agents. Non-ferrous metals such as anodised

aluminium are acceptable. Master

film may be stored in acid free boxes.

c. Only conservation materials

(paper, glues, labels and adhesives) that have been

approved or tested under photographic activity test (PAT)

should be used to store microfilm of long term retention.

For details of PAT, please refer to ISO 18916:2007.

6.5 Disposal Requirements for Source Documents and

Microfilm Records

a. For any micrographic project involving the conversion of paper records to

microform, the records should be scheduled as part of the process of approving the

project. Scheduling of the records shall be undertaken in conjunction with the

Records Management and Administration Office and the Public Records Office of

GRS. A Retention and Disposal Authority which approves the agreed retention and

disposal arrangement should be obtained from the GRS Director.

b. After microfilming is completed, source documents are usually destroyed and only

the microfilm copy is retained. Destruction of the hard copies of documents should

be undertaken in accordance with the relevant Records Retention and Disposal

Schedule and subject to prior agreement of the GRS Director.

c. Both inactive source documents and microfilm copies are eligible for disposal when

they are no longer required for use and after the retention period as set out in the

relevant Records Retention and Disposal Schedule.

Microfilm Cabinet

Microfilm Supplies

44

6.6 Microfilm Standards

The establishment and application of microfilm standards can insure the image

longevity, image quality, and legality of microfilm records. When microfilm becomes

the substitute for paper, this assurance is necessary to ease the transition of the record

media.

a. Image Longevity

The life expectancy and stability of microfilm means the image and quality will last as

long as the record is needed. Image longevity and stability requirements are set forth in

ISO 18901:2010.

b. Image Quality

The quality of film is determined by its density, resolution and general legibility. An

excellent source of image quality guideline is ANSI/AIIM MS 23-2004 that discusses

equipment, supplies, and recommended practices necessary to establish and operate a

satisfactory micrographic programme for silver gelatine film.

c. Court Admissibility

Microfilm of both business and government records is generally court admissible

according to the Evidence Ordinance (Cap. 8).

The following are some microfilming standards widely adopted in countries in North

America, Europe and Australia:

ANSI/AIIM TR13-1998 Preservation of microforms in an active

environment - Guidelines

ISO/TR 10593:1997 Micrographics - Use of microfilm jackets

ISO/TR 12031:2000 Micrographics - Inspection of silver-gelatin

microforms for evidence of deterioration

ISO/TR 18931:2001 Imaging materials - Recommendations for humidity

measurement and control

ANSI/AIIM MS14-1996 Specifications for 16mm and 35mm Roll Microfilm

ANSI/AIIM MS18-1992

(R1998)

Micrographics - Splices for Imaged Film -

Dimensions and Operational Constraints

ANSI/AIIM MS19-1993 Recommended Practice for Identification of

Microforms

45

ANSI/AIIM MS23-2004 Recommended Practice - Production, Inspection,

and Quality Assurance of First-Generation, Silver

Microforms of Documents

ANSI/AIIM MS35-1990 Recommended Practice for the Requirements and

Characteristics of Original Documents That May Be

Microfilmed

ANSI/AIIM MS48-1999 Recommended Practice for Microfilming Public

Records on Silver Halide Film

ISO 6199:2005 Micrographics - Microfilming of documents on 16

mm and 35 mm silver-gelatin type microfilm -

Operating procedures

ISO 6200:1999 Micrographics - First generation silver-gelatin

microforms of source documents - Density

specifications and method of measurement

ISO 8126:2000 Micrographics - Duplicating film, silver, diazo and

vesicular - Visual density - Specifications and

measurement

ISO 18901:2010 Imaging materials - Processed silver-gelatin-type

black-and-white films - Specifications for stability

ISO 11962:2002/

Cor 1:2006

Micrographics - Image mark (blip) used with 16

mm and 35 mm roll microfilm

ISO 18901:2010 Imaging materials - Processed silver-gelatin type

black-and-white films - Specifications for stability

ISO 18902:2007/

Cor 1:2009

Imaging materials - Processed imaging materials -

Albums, framing and storage materials

ISO 18911:2010 Imaging materials - Processed safety photographic

films - Storage practices

ISO 18916:2007 Photography - Processed photographic materials -

Photographic activity test for enclosure materials

ISO 18917:1999 Photography - Determination of residual thiosulfate

and other related chemicals in processed

photographic materials - Methods using iodine-

amylose, methylene blue and silver sulfide

46

Glossary

Aperture card

Aperture card is a card with a rectangular hole(s) specifically prepared for the insertion

or mounting of a frame of microfilm.

Archival film

A processed film that is suitable for permanent preservation of records when properly

processed and stored.

Archival quality

The ability of a processed film to permanently retain its original characteristics and the

ability to resist deterioration for a lengthy specified time.

Background density

The opacity of the non-information area of an image.

Bar code

An array of vertical rectangular marks and spaces in a predetermined pattern.

Blip mark

An optical mark within the recording area below or above the image on a roll film. The

mark is used to locate images or frames on microfilm.

Camera film

Camera film is the first-generation film used in capturing the image of source document

in the microfilm camera; also known as the master film.

Cartridge

Cartridge is a container enclosing processed roll microfilm. A cartridge is designed to

be inserted into readers, reader-printers and retrieval devices and used with a single

core for roll microfilm.

Cellulose ester

It is a film base composed mainly of cellulose esters of acetic, propionic or butyric

acids or mixtures thereof.

Cine mode

Cine mode is filming mode in which orientation of images are arranged in the same

direction as the length of the microfilm (as in a motion picture film).

47

Comic mode

Comic mode is filming mode in which orientation of images are perpendicular to the

length of the microfilm (as in a comic strip).

Computer assisted retrieval system (CAR)

The capability of having micrographic images located or identified by a command

initiated through a computer terminal.

Computer input microfilm (CIM)

Computer input microfilm is the process of reading data contained on microfilm by a

scanning device and transforming this data into a form readily for computer processing.

Computer output microfilm (COM)

Microforms containing data produced by a recorder from computer-generated electrical

signals. A computer output microfilmer converts data from a computer and records it

into microfilm.

Conventional processing

Conventional processing is a series of steps consisting of developing, fixing, washing,

and drying.

Correction target

A target used to notify that a filming error has been made and that a correction will

follow.

Densitometer

An instrument used to measure the optical density of an image by measuring the

amount of incident light transmitted by the film.

Diazo film

A photographic film containing light-sensitive layers composed of diazonium salts that

react with couplers to form diazo dye images after film processing. It is a duplicating

film using an ultraviolet light and ammonia process to produce non-reversing images,

i.e., a positive image will produce a positive image and a negative image will produce a

negative image.

Direct image film

A film that retains the same polarity as the original material; that is, negative for

negative, or positive for positive with conventional processing.

Document preparation

The process of preparing documents readily to be microfilmed. This includes sorting

and flattening documents, and removing staples and paper clips.

48

Dry silver film

A non-gelatine silver film which is developed by application of heat.

Duo

A method of capturing images on each half of the usable width of the microfilm in

which the microimages are made first on one half and then continued on the other half

in the reverse direction.

Duplex

A method of capturing images in one exposure that the front and back of a document

are filmed at the same time. The microimages appear side by side across the width of

the microfilm.

Emulsion

Emulsion is a single or multi-layered coating of light-sensitive material on the

microfilm surface that creates a latent image during exposure.

Emulsion number

Number used by film manufacturers to identify coating data for each roll of film.

Endorser

Endorser is a camera accessory that automatically stamps documents as they are filmed.

Film base

Film base acts as a support for the film and provides an area for the emulsion to reside.

Film leader

Blank microfilm at the beginning of a roll that is used for protection and for threading

the film into camera, reader, or processing equipment.

Film strip

Film strip is a short strip of processed film containing a number of frames.

Film trailer

Blank microfilm at the end of a roll that is used to thread film into equipment.

Flash target

Flash target is a target with distinctive markings to facilitate indexing of the film.

Frame

The area of a photographic film exposed to light in a camera during one exposure no

matter whether this area is filled by the document.

49

Generation

A measure of the successive stages of photographic reproduction from an original or

master. The first generation is the camera film. Copies made from this generation are

second generation, from the second generation are third generation, etc.

Image

A representation of an object on microfilm produced by light rays.

Image mark

Image mark is a rectangular mark either above or below the image that can be sensed

and counted by reader /reader-printer for fast frame retrieval.

Image orientation

Image orientation is the arrangement of images with respect to the edges of the film.

Jacket

Jacket is a transparent plastic carrier with pockets made to hold microfilm in flat strips.

Microfiche

Microfiche is a transparent sheet of film (usually 105mm) with microimages arranged

in a grid pattern, with a heading area across the top.

Microfilm reader

Microfilm reader is a device for viewing enlarged microimages of microfilm.

Microfilm reader-printer

Microfilm reader-printer is a machine which combines the functions of a reader and a

printer.

Planetary camera (flatbed camera)

A type of microfilm camera that produces either 16mm or 35mm film. It is a camera in

which the document being photographed and the film remain in a stationary position

during filming. A planetary camera is designed to make precision microimages of

detailed manuscripts.

Polyester

It is a transparent plastic made from polyesters and used as a film base because of its

stability, strength, resistance to tearing and relative non-inflammability.

Printing master

A microfilm used to make duplicates. Printing master is usually the second generation

film made from processed camera master film.

50

Processing

Processing is the treatment of exposed photographic material to make the latent image

visible. It involves a series of steps consisting of developing, fixing, washing, and

drying.

Quality Index (QI)

QI is the relationship between legibility of printed text and the resolution pattern

resolved in a microimage.

Reduction ratio

It is the relationship between the dimensions of the original document and the

corresponding dimensions of a microimage, usually expressed as 16X, 24X, etc.

Residual thiosulphate ion

Residual thiosulphate ion is a chemical component (ammonium or sodium thiosulphate)

remaining in film after processing. High level of residual thiosulphate would cause

fading of the microimages in the microfilm. The level of residual thiosulphate is

determined by methylene blue test.

Resolution

Resolution is the ability of a photographic system to record fine details of an object; a

measure of sharpness of an image, expressed as the number of lines per millimetre.

Rotary camera

A type of microfilm camera that produces 16mm film only. It photographs documents

when they are being moved by a transport mechanism. It is used to film loose papers

and forms quickly.

Silver gelatine film

Silver gelatine film is a photographic film coated with a silver halide emulsion. Silver

gelatine film is used to create microfilm originals.

Silver halide

Silver halide is a compound of silver and one of the following elements known as

halogens: chlorine, bromine, iodine and fluorine.

Splicer

A device for joining strips of microfilm.

Step and repeat camera

A type of microfilm camera that produces 105mm film in the same manner as planetary

cameras. This type of camera produces images in orderly rows and columns on

microfiche.

51

Target

Target is a chart containing identification information or coding photographed on the

film preceding or following the document. Targets include titleboards, technical targets

(resolution test chart), control targets and quality targets.

Titleboard

A target containing a description of the records being filmed and technical information

about the filming.

Updatable microfilm

A microfilm that permits the addition or deletion of images.

Vesicular film

A film containing photosensitive layers composed of diazonium salts in a thermoplastic

material. On exposure the salts are decomposed to create optical vesicles (bubbles)

which form the latent image, which is developed by the application of heat.

52

Appendix A

53

Appendix A

54

Appendix B

55

Appendix B

56

Appendix C

57

Appendix D

58

Appendix E Samples of Filming Targets

Statement of Intent and Purpose Titleboard

59

Appendix E Samples of Filming Targets

60

Appendix F

Source: ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents, p. 98. 59

61

Appendix G

Source: ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents, p. 79.

62

Appendix H

Resolution Test Chart for Planetary Camera

Source: ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents, p. 35.

63

Appendix I

Resolution Test Chart for Rotary Camera

Source: ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents, p. 36.

64

Suggested Reading

Books

Avedon, Don M. and Rodd Exelbert, All About Micrographics. Avedon Associates Inc.

Maryland 1990.

Fox, Lisa L., Preservation Microfilming: A Guide for Librarians and Archivists, 2nd

edition. American Library Association, Chicago and London 1996.

Jones, Virginia A., Handbook of Microfilm Technology and Procedures, 4th edition.

QP Publishing, Crestview 1995.

Justrell, R., Michael Roper and Herbert White, Guidelines for the Preservation of

Microforms. International Council on Archives, Paris 1996.

National Library of Australia. Guidelines for Preservation Microfilming in Australia

and New Zealand. Canberra 1998.

Ricks, R., Ann Swafford and Kay Gow, Information and Image Management - A

Records Systems Approach, 3rd edition. South-Western Publishing Co., Ohio 1992.

Saffady, William. Micrographics Systems, 3rd edition. Association for Information and

Image Management, Maryland 1990.

Vilhauer, Jerry. Introduction to Micrographics. Association for Information and Image

Management, Maryland 1991.

Standards

ANSI/AIIM MS14-1996 Standard Recommended Practice - Specifications for 16mm

and 35mm Roll Microfilm. Association for Information and Image Management

International, Maryland, 1996.

ANSI/AIIM MS17-2001 Micrographics - Rotary (Flow) Microfilm Camera Test Chart

and Test Target - Description and Use. Association for Information and Image

Management International, Maryland, 2001.

ANSI/AIIM MS23-2004 Standard Recommended Practice - Production, Inspection, and

Quality Assurance of First-Generation, Silver Microforms of Documents. Association

for Information and Image Management International, Maryland, 2004.

65

ANSI/AIIM MS43-1998 Standard Recommended Practice - Operational Procedures -

Inspection and Quality Control of Duplicate Microforms of Documents and from COM.

Association for Information and Image Management International, Maryland, 1998.

ANSI/AIIM MS45-1990 Recommended Practice for Inspection of Stored Silver -

Gelatin Microforms for Evidence of Deterioration. Association for Information and

Image Management International, Maryland, 1990.

ANSI/AIIM MS51-1991 (ANSI/ISO 3334-1991) Micrographics - ISO Resolution Test

Chart No. 2 - Description and Use. Association for Information and Image Management

International, Maryland, 1991.

ANSI/AIIM TR13-1998 Technical Report - Preservation of Microforms in an Active

Environment - Guideline. Association for Information and Image Management

International, Maryland, 1998.

ISO 18901:2010 Imaging materials - Processed silver-gelatin type black-and-white

films - Specifications for stability. International Organization for Standardization, 2010.

ISO 18911:2010 Imaging materials - Processed safety photographic films - Storage

practices. International Organization for Standardization, 2010.

ISO 18916:2007 Photography - Processed photographic materials - Photographic

activity test for enclosure materials. International Organization for Standardization,

2007.

ISO 18917:1999 Photography - Determination of residual thiosulfate and other related

chemicals in processed photographic materials - Methods using iodine-amylose,

methylene blue and silver sulphide. International Organization for Standardization,

1998.